Table 1.

Trial types used in Test Phase 2

Trial type	Description of correct arm contents	Example trial
First Numerals Equal [Second Varied]	Numerals in the first position of each arm are the same; correct arm choice depends on the numerals in the second position	2 + 3; 2 + 2
Second Numerals Equal [First Varied]	Numerals in the second position of each arm are the same; correct arm choice depends on the numerals in the first position	3 + 3; 4 + 3
First Numeral Larger [Second Smaller] for Arm with Larger Total	The arm with the larger sum had a larger first numeral and a smaller second numeral compared to the other arm	5 + 1; 1 + 4
First Numeral Smaller [Second Larger] for Arm with Larger Total	The arm with the larger sum had a smaller first numeral and a larger second numeral compared to the other arm	4 + 1; 3 + 4

Correct arm in bold

Note. For all trial types, the difference between sums in the two arms could be 1, 2, or 3 total items, except for First Numerals Equal [Second Varied], which could only have a difference of 1 or 2